


A Little Warm

by Nanenna



Series: A Little Series [4]
Category: Undertale (Video Game)
Genre: Afterdeath (Undertale Ship), Aftertale Sans (Undertale) - Freeform, Aftertale Sans/Reapertale Sans (Undertale), Alternate Universe, Alternate Universe - Aftertale (Undertale), Alternate Universe - Reapertale (Undertale), Alternate Universe - Twins, Established Relationship, Fluff and Humor, Future EverAfterDeath (Undertale Ship), Implied/Referenced Sex, M/M, Mild Language, Permanent Injury, Reapertale Sans (Undertale), Relationship Discussions, eventual poly - Freeform
Language: English
Status: Completed
Published: 2020-02-25
Updated: 2020-02-25
Packaged: 2021-02-28 04:15:02
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,108
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22887658
Author URL: https://archiveofourown.org/users/Nanenna/pseuds/Nanenna
Summary: Reaper's tired and just wants to relax, but is it getting warm in here or is it just Geno and Cider?
Relationships: Sans/Sans (Undertale)
Series: A Little Series [4]
Series URL: https://archiveofourown.org/series/1610887
Comments: 16
Kudos: 71





	A Little Warm

**Author's Note:**

> A heat fic with no actual sex? It's more likely than you think.

It had been a long, long day. In all honesty Reaper was pretty sure it was closer to three days (it was hard to keep track of time when every universe and timeline was on a different date, not to mention time zones). Several new AUs had popped into existence, each one with its own war between humans and monsters, plus it seemed like every single last fallen human had decided to go on a genocide run (now **there** was a Sisyphean task) all at once. Even though technically gods don’t need sleep, Reaper felt exhausted and ready to fall into bed. He was glad to have finally reaped enough Souls to quiet the noise in his head and go home.

The moment he stepped into their home a familiar sweet scent hit him, and hit him hard. Far harder than it should be able to for only being gone maybe three days. “geno?”

“r-reaper!”

That definitely sounded needy. “geno, why didn’t you text me?” He rounded into the living room to find Geno and Cider wrapped up in each other’s arms, legs tangled over laps and around waists, both sporting faint blushes and the slightly brighter glow to their Souls that heralded the start of preheat.

“it just barely started. besides, it’s not so bad with cider here.”

“heats suck,” Cider murmured as he snuggled somehow deeper into Geno’s hold. One of Geno’s hands fluttered along Cider’s arm, like he couldn’t decide between clinging to Cider or reaching for Reaper.

“c’mere, the both of you,” Reaper said while trying to hide his laugh. He drifted close enough to pull the pair into his arms, they both latched on like koalas. Little, red, glitching, skeleton koalas. They squirmed and shifted, arms flung over his shoulders or each others’, legs wrapped around ribs and waists and hips, Geno ripped off the little clasp and rope that kept the top of Reaper’s robe closed and shoved his whole arm inside, Cider tentatively put a hand on Reaper’s partially exposed clavicle, then the pair were snuggling their skulls onto his shoulder and the crook of his neck with happy little murmurs. Reaper smiled down at Cider’s hesitance, “it’s alright, i know bone on bone contact is best.”

Cider made a garbled little noise and hid his face in Reaper’s neck, adorable. Geno sighed happily and snuggled in, Reaper decided to turn and sit down on the couch with his two armfuls of glitchy, touch starved skeleton. Reaper let out a happy sigh of his own once the three of them were settled in comfortably. Geno may hate preheats (far less now that he had Reaper to take care of him like he deserves), but Reaper found them to be relaxing. He got to just sit around with his favorite person in the whole multiverse and do nothing but cuddle for a while.

Speaking of favorite person, he should let Respite know what’s going on. It took a bit of digging, some grumbling from Geno, and an interesting balancing act of typing out a message without letting either one go, but Reaper managed to get the message typed out and his phone moved to the nearby coffee table. Then he got to just sit back and relax for a while. Later he’d have to get up and gather all the supplies they’d need once the preheat transitioned into a full on heat and Geno’s clothes became too uncomfortable to keep wearing. Geno and Cider both, Reaper should say.

Reaper stiffened, Cider was in preheat too. Which meant that he was going to go into heat right alongside Geno, but Reaper wasn’t dating Cider (yet). Reaper cursed internally, what should they do? Would Cider want Reaper to help him through it? No wait, they hadn’t discussed it before and even though his heat hadn’t actually started yet Cider’s inhibition would already be compromised. No, Reaper absolutely would not do anything to hurt Cider’s or Geno’s trust. He would be a gentleman and let Cider take care of himself. While Reaper and Geno were just on the other side of their “house.”

Yeah, no. Even in someplace with actual walls that was not really a good idea. The best they could hope for was enough space between them for more than just the illusion of privacy, so a lot of space. Enough that they couldn’t even see the house anymore, like at one of their previous date spots. Yeah, there were a few sprinkled around, that should work. He just needed to gather up all the supplies they would need and take Geno to one of those spots.

Reaper started compiling a list of all the things they would need as he relaxed back into the couch. Snacks and drinks, enough for all three of them. What else? Perhaps some blankets and pillows depending on which spot Geno chose, Cider was staying here so his bed should be plenty. Maybe Reaper should pack a few choice toys while he was at it, Geno did like some of their more risque games while he was in heat. Would Cider want any too? Should he ask or would it be weird to offer some of their toys to his boyfriend’s time shenaniganned duplicate? No wait, no matter how thoroughly they’d been washed, offering used toys to anyone was weird!

Something hard was poking Reaper’s cheek. “there’s smoke coming out of your ears, stop thinking so hard.”

“we don’t even have ears,” Reaper replied to Geno with a laugh.

“well stop anyway, you’re slacking on the cuddling. stop thinking and get to work.”

“what’re you talking about? he’s doing great.” Cider nuzzled Reaper’s shoulder with a contented sigh.

Reaper smirked as he started rubbing up and down his two glitches’ spines through their hoodies. Cider sputtered and stiffened in surprise, then seemed to melt into Reaper’s hold with a contented sigh. His fingers flexed where they clung to Reaper’s clavicle, it rather reminded Reaper of a cat kneading in happiness.

“mmmm… yeah… don’t stop,” Geno all but purred.

“i am going to have to stop eventually to get everything set up for us.”

“later,” Geno groused, then went back to nuzzling happily into Reaper’s neck.

“sir, yes, sir,” Reaper said jokingly, not letting their banter interrupt his slow, firm strokes up and down their backs. Peace fell on the three of them, a silence born of contentedness but also heavy as the calm before the storm. A sexy, sexy storm that wore a white hoodie and had a grumpy face and turned into the cutest little desperate sub when he was in heat.

Reaper relaxed and let the silence wash over them. It was so quiet he could faintly hear the sound of Geno’s and Cider’s glitches under the sound of their breathing. It was the usual bubbly sound that reminded Reaper of those colorful phone games. He pressed more firmly into Cider’s and Geno’s backs, to Reaper’s delight the sound of Geno’s glitches changed from bubbles to high pitched beeps and chirps. Then the chirps grew more frequent and went from mono to stereo.

Holy shit, Cider was glitching happily too! Reaper couldn’t help grinning to himself as he settled deeper into the couch, hugging the two preheat monsters as close as monsterly possible. Once as settled as he could possibly get, Reaper let his skull roll to rest on top of Geno’s, content to sit and listen to his and Cider’s contentment until it was time to get the show on the road.

* * *

Geno was starting to get pretty squirmy. Cider too, even if less so. Reaper could ignore it for a bit longer, but he was pretty sure that would be a bad idea when he had twice as much getting ready to do. “you two hungry?”

“nuoooooooo…”

“uh, a little.”

“nwuoooooooooooooooooooooo…”

“geno,” Reaper lightly chided.

“i don’t wanna get up,” Geno admitted grumpily.

“and you don’t have to.” Reaper held them both a little tighter as he stood and drifted into the kitchen. This wasn’t his first heat rodeo, after all, he knew what he was doing. He could easily switch Geno to a one armed hold and use his free hand to gather everything they would need.

The one armed hold Geno was already in. Because Cider was in his other arm.

“uuuuuuuuuuuuh…” Reaper stared at the fridge handle, then down to the two glitches in his arms.

Cider clung all the harder, “don’t you dare let go.”

Huh, not the one Reaper had expected to protest. “just while i gather supplies.”

“nuh uh.” Okay, there was Geno’s expected protest.

“you can support yourselves, just hold on while i grab us some snacks.”

“nope.”

“well you two kept each other company just fine, i’ll just set the both of you down together…”

There was a mix of static, pops, hissing, and a stuttering, high pitched whine along with their protests.

“then keep holding on, but i need my hands.”

“ugh! fine.” Geno and Cider both squirmed until they had Reaper in a (heh) death grip, but Reaper would survive.

He started humming a jaunty tune as he opened the fridge and began pulling everything out. Some of it was even finger foods, nice! And oh! A little four pack of coffee in those weirdly tall, slim cans, Reaper had forgotten those were in there. Those would be useful, he set them on the counter next to everything else. Now he just needed to separate everything out into portions. Let’s see, did they have any little baggies or containers left over from his last fast food run? No? What else? He could just use the containers they were already in, but that wouldn’t give them a nice little variety. Maybe plates? They had plates, it would take doing some extra trips but it would work. Reaper added a little bounce and sway to his step as he hummed his way over to the cupboard with the plates in it.

“you sure are cheerful.”

“i’m just thinking of all the things i’m gonna do to you once your heat hits,” Reaper purred as he nuzzled into Cider’s skull.

Wait, Cider’s skull? Shit.

“uuuuuuuuh…”

“did you just?” Geno asked with a laugh.

“shit.” Reaper tried to jump away from Cider, which did about as much good as you would think jumping away from a veritable koala already clinging to you would do. “sorry, cider. i uh… shit, i got you two messed up.” He felt mana rush to his face, he must be glowing with it.

“clearly.” Cider was blushing bright red under his glitches, the other half of his face hidden in Reaper’s shoulder. The good half, unfortunately, so Reaper had no idea what his expression was.

“i’m sorry, i’m so, so sorry! i was trying so hard not to mix you two up!”

“you’ve done a pretty stellar job so far, this is the first time it’s ever happened.” Geno gently pat Reaper’s sternum.

“and uh… i mean… if you really want i uh…”

“no.” Reaper put a hand up, though with Geno clinging to him he couldn’t actually cover Cider’s mouth even if he wanted to. “no, it’s not about what i want. more than that: it’s about consent, which you didn’t give before this started. so no, i won’t be doing anything to you once your heat starts. and uh, geno? wanna pick where we go? one of our date spots, i want to give cider and us some privacy.”

“i’ll think about it,” Geno said, though he was looking sternly at Cider the whole time. Then his head tilted at an odd angle, “not the beach though, i don’t want sand in my joints again.”

Reaper laughed at that, “reasonable.” He started humming again as he went back to dividing up their goodies between them.

Cider nuzzled into Reaper’s neck, the most intimate he’d been since this whole thing started, “thanks.”

“you’re welcome,” Reaper replied with a gentle smile.

“told ya,” Geno said smugly.

“told him what?” Reaper asked.

“later, i want one of those cookies right now.”

“oh! me too.” Cider and Geno both spared a hand to make grabby motions at the platter of cookies sitting in the middle of the dinner table, covered by a tea towel for some reason.

Reaper laughed but obligingly pulled the platter closer and the towel off, letting his two glitches stuff a handful of cookies each into their mouths. He couldn’t help the fond smile that spread across his face. Soon (hopefully) they would both actually be his, his two little darling Sans Genocide Gasters. What a day that would be.


End file.
